This finding was inconsistent with a previous report of downregulated occludin in normal and asthmatic primary human bronchial cells, human lung epithelial cells, and sinonasal epithelial biopsies from patients with chronic rhinosinusitis, induced by the activity of IL-4/13 and histone deacetylases [5, 17, 18, 20, 41, 46]. Here, IL4 is linked to chronic rhinosinusitis.